Four Wooden Stakes by Victor Roman

A man receives an urgent dispatch from an old college friend to immediately come to his remote estate. Here, the man learns how, within five years, his friend’s entire family—grandfather, father, and two brothers—died of a mysterious malady. Even worse, the friend is growing weaker, despite consuming voracious amounts of food, and fears the same fate. The family crypt holds the secret. First published in 1925 and available for free reading online.